On Thu, Feb 04, 2016 at 06:29:00PM +0100, Tomasz Nowicki wrote:
This is the last step before enabling generic ACPI PCI host controller for ARM64. We need to take care of legacy IRQ mapping for non-MSI(X) PCI devices. pcibios_enable_device() boot order is not sensitive to ACPI device enumeration, so it is the best place to assign device's IRQs.
I guess you are referring to:
https://lists.linaro.org/pipermail/linaro-acpi/2015-October/005944.html
It is weird that the dependency can't be enforced, I will have a look into this, it would be nice to have DT and ACPI legacy IRQs mapping confined in pcibios_add_device() so that we can remove them in one go when Matthew's series is merged.
As for the MSI check, by reading commit history its need I think it harks back to bba6f6fc, which was supposed to be a quick hack and it has been in the kernel for 9 years :), is it really needed ?
NOTE: *This is going to be temporary solution*. There is ongoing work which aims for cleaning legacy IRQ allocation, see [1]. We can consider this patch as the necessary evil which will be removed once [1] series hits mailnline in the near future.
Signed-off-by: Tomasz Nowicki tn@semihalf.com
arch/arm64/kernel/pci.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 023b983..d1a701f 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -39,16 +39,26 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, } /**
- pcibios_enable_device - Enable I/O and memory.
*/
- pcibios_enable_device - Enable I/O, memory and legacy IRQs for ACPI.
- @dev: PCI device to be enabled
- @mask: bitmask of BARs to enable
int pcibios_enable_device(struct pci_dev *dev, int mask) {
- int ret;
- if (pci_has_flag(PCI_PROBE_ONLY)) return 0;
- return pci_enable_resources(dev, mask);
- ret = pci_enable_resources(dev, mask);
- if (ret < 0)
return ret;
+#ifdef CONFIG_ACPI
- if (!pci_dev_msi_enabled(dev))
return acpi_pci_irq_enable(dev);
You need a guard here anyway, we do not want to probe ACPI IRQ if it is disabled (ie acpi_pci_disabled). Same goes for DT in pcibios_add_device(), which is not making this code any nicer.
Lorenzo
+#endif
- return 0;
} /* -- 1.9.1